1. Field of the Invention
The present invention relates to an air inflatable seat cushion. More specifically, the invention is an alternating pressure cushion for therapeutic or medical use. The cushion is useful for preventing and treating decubitus ulcers in hemodialysis patients and others who are prone to decubitus ulcers from sitting for extended periods while receiving dialysis or other forms of treatment.
2. Description of the Related Art
Decubitis ulcers, more commonly known as pressure sores or bedsores, are a common problem that afflicts people who are debilitated, confined to a bed, or otherwise immobilized. Decubitus ulcers, which are areas of skin and tissue that become ulcerated from pressure caused by lying down in the same position for extended or prolonged periods of time, form when the skin and underlying tissue are pressed between a bone and an external surface, such as a bed or chair. Pressure restricts blood flow to these areas. After a prolonged period the reduced blood flow begins to cause tissue damage that, if left unchecked, may become severe.
Avoiding prolonged pressure to parts of the body can prevent decubitus ulcers. Bed-ridden patients should be moved to relieve pressure points. Also, various cushions, pillows, foam padding and the like can be used to prevent pressure points for bed-ridden patients and patients who are confined to a seated position, such as hemodialysis patients and the wheelchair-bound.
Mattresses have been devised to provide for distribution of pressure and the prevention of bedsores in bed-ridden patients. Mattresses for decubitis relief are often known as xe2x80x9cturning mattressesxe2x80x9d because they typically employ air bladders or another mechanism to gently turn a bed-ridden patient from side to side, changing the side of the patient""s body that is weighted. In addition, cushions for chairs and wheelchairs that reduce or redistribute pressure are known.
Hemodialysis patients present a particular need, since a patient undergoing hemodialysis may be moved through a range of positions, from being seated upright, to a partially reclined position, to being fully reclined. During the hemodialysis session, the patient must remain in the hemodialysis chair for several hours, thus creating a risk of pressure sores. Because the patient may be in a reclined position, there is a risk of pressure sores on the patient""s legs, buttocks, and back. Thus, a simple seat cushion is insufficient to protect the patient""s legs and back from pressure points.
A turning mattress is not suited to the needs of hemodialysis because a fully recumbent position is not generally preferred, and because the turning of the patient is not desirable while the patient is connected to the intravenous hemodialysis lines. For a hemodialysis situation, a cushion that is segmented to provide pressure relief for the legs, buttocks, and back and that is flexible to accommodate various degrees of recline is needed.
U.S. Pat. No. 3,987,507, issued on Oct. 26, 1976 to M. Hall, discloses a pressure distribution pad assembly for wheelchairs. The pad is formed of a foam material and has regions of greater and lesser density to evenly distribute pressure when a person sits on the pad on a wheelchair. This pad, however, is only a seat pad and provides relief only for the buttocks.
U.S. Pat. No. 4,729,598, issued on Mar. 8, 1988 to J. Hess, describes a patient chair system that includes features to prevent pressure sores. The chair utilizes air sacs to form a support for the buttocks and thighs of a patient to distribute weight and eliminate pressure points. Again, while providing relief to a seated patient, this chair system does not address the needs of a patient who is in either a partially or fully reclined position.
U.S. Pat. No. 5,619,764, issued on Apr. 15, 1997 to H. Lopau, discloses a mattress for decubitus prophylaxis. A kind of xe2x80x9cturning mattress,xe2x80x9d the mattress includes inflatable air chambers that form a pair of longitudinal air cushions. The pair of air cushions, one on each side of the mattress, are separately inflatable and deflatable. In use, each of the pair is alternately inflated and deflated, causing the patient to be turned gently from side to side. Because the patient is turned from side to side, continuous pressure points are avoided and bedsores may be prevented. Although this mattress provides for full body prevention of bedsores, the method of turning a patient from side to side is not suitable for use in a seated position, and in a hemodialysis situation it is preferred not to turn the patient while connected to the intravenous hemodialysis lines. Additionally, because the mattress is designed generally for patients in a recumbent position and not a seated position, it lacks some features which are desirable for patients in a seated position, such as a lumbar support.
French Patent No. 2,601,874, published on Jan. 29, 1988, discloses another air mattress for prevention of bedsores in a bedridden patient. The primary benefit of this mattress appears to be its construction with a material that is highly permeable to water vapor, allowing the mattress to xe2x80x9cbreathe.xe2x80x9d Again, this mattress is designed for recumbent bed-ridden patients, and so lacks features that are desirable for seated use.
U.S. Pat. No. 5,893,184, issued on Apr. 13, 1999 to M. Murphy, discloses a pressure reducing backrest cushion with pressure point relief. The cushion is comprised of several air bladders, each filled with a compressible foam material. The foam material provides support in conjunction with air contained within the air bladders. Pressure points may be relieved by letting air escape from one or more of the bladders that support the pressured region. The cushion provides enhanced comfort by the ability to adjust firmness of various portions by expelling air from the bladders. However, once a bladder is deflated it will not re-inflate until the patient has moved or stood up to allow the foam to expand. This cushion, therefore, is not ideally suited for a situation where a patient is confined to a seated or reclined position for an extended period. Also, patient comfort may be compromised by the lack of a lumbar support.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus an alternating pressure cushion solving the aforementioned problems is desired.
The alternating pressure cushion is a seat cushion for the prevention and treatment of decubitis ulcers in patients who are required to sit in an upright or reclined position for an extended period of time, such as hemodialysis patients undergoing a lengthy treatment. Hemodialysis patients, patients confined to a wheelchair, patients who are bed-ridden, and other patients with limited mobility may use the cushion to provide comfort and to avoid pressure points that cause pressure sores.
The cushion is formed in three sections to provide a back cushion, a seat cushion, and a leg cushion. Each of the sections contains a plurality of air bladders. Air channels connect the air bladders between sections to form air bladder networks, each of which can be inflated and deflated from a single source.
The air bladders are arranged so that each bladder network provides uniform support not dependant on the other bladder networks. In use, the bladder networks are alternately inflated and deflated so that as one is inflated, another is deflated. The alternate inflation of each bladder network allows the patient""s weight to be shifted from one network to another network, thereby eliminating prolonged pressure points.
The back cushion has a separately inflatable air bladder that forms a lumbar support region for improved comfort.
Accordingly, it is a principal object of the invention to provide an alternating pressure cushion for the prevention and treatment of pressure sores.
It is another object of the invention to provide an alternating pressure cushion for the prevention and treatment of pressure sores that includes back, seat, and leg support cushions.
It is a further object of the invention to provide an alternating pressure cushion for the prevention and treatment of pressure sores that includes a lumbar support for additional comfort.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.